Field
Exemplary embodiments of the present invention relate to a technology for a light emitting device and a method of fabricating the same, including a light emitting device having a wide beam angle by virtue of surface treatment and the like, and a method of fabricating the same.
Discussion of the Background
Light emitting devices are inorganic semiconductor devices emitting light generated by recombination of electrons and holes, and are used in a variety of fields such as displays, vehicle lamps, general lighting devices, and the like. Since nitride semiconductors, such as a gallium nitride semiconductor and a gallium aluminum semiconductor, may be of a direct transition type and may be fabricated to have various energy band gaps, the nitride semiconductors may be used to fabricate light emitting devices having various wavelength emission ranges as needed.
Light emitting devices are required to have various ranges of beam angles depending upon applications thereof. For example, it is advantageous that UV light emitting devices applied to backlight units of displays, sterilizers, and the like have wide beam angles. Therefore, additional components such as a lens, or a technique such as surface treatment are used to increase beam angles of the light emitting devices.
For wafer level packages having no separate package body, or chip-on-board type light emitting devices, it is necessary to adjust beam angles thereof without an additional component, such as a lens. However, although typical surface processing techniques can increase light extraction efficiency of light emitting devices, there is difficulty in increasing the beam angles thereof. Particularly, since it is undesirable that an injection-molded component or lens made of a material, which can be deformed or degraded by UV light, be applied to UV light emitting devices, there is a limit in application of techniques for increasing beam angles.
In addition, typical flip chip type light emitting devices have a problem in that even a sapphire substrate having a thickness of 400 μm or greater has difficulty in realizing a wide beam angle of 140° or more, and that, as the thickness of the sapphire substrate increases, luminous efficiency decreases.
Therefore, there is a need for techniques for increasing a beam angle of a light emitting device not employing a package body or a lens.